Compact vehicles to which the present invention is directed are those that are defined in Non-Patent Document No. 1 as “ultra-compact vehicles”, or “one- or two-seater vehicles that are more compact and more maneuverable than cars, have an excellent environmental performance, and offer a local, affordable means of transportation”. Such a compact vehicle typically includes only one seat in the lateral direction, and is more compact and has a smaller vehicle width as compared with an ordinary car including two or more seats laterally in parallel, and it therefore imposes less burden on the road, traffic, and parking space; the body weight thereof is less than that of an ordinary car, and it can therefore reduce the environment burden by reducing CO2, for example. Therefore, with such advantages, it is expecting an increasing demand in the future.
As with the one described in Patent Document No. 1, for example, such a compact vehicle includes only one driver seat in the lateral direction of the vehicle, with a frame covering the front side, the rear side, the upper side and the lower side of the seat, with an opening left open on the side of the seat for allowing a passenger to get on/off, and a door for shutting the opening is omitted in order to ensure passenger accessibility in a small parking space and realize a small weight.
A structure is employed, in which in order to allow a passenger to get on/off a passenger seat located on the rear side of the driver seat, the driver seat is movable without interfering the steering handle of the vehicle by swiveling within the vehicle chamber about an axial point provided on the frame above the vehicle.
With the structure described in Patent Document No. 2, rod-shaped side bars are provided in the opening on the side of the seat, wherein the side bars can be flipped up above the vehicle, thereby protecting the passenger and ensuring accessibility in a narrow parking space.
Patent Document No. 3 proposes various embodiments of vehicles aiming at increasing the space efficiency of the vehicle, making it easier for the driver and the passenger in the back to get on/off, and further improving the passenger protection, wherein the sixth embodiment and the seventh embodiment propose vehicles that are stretchable in the longitudinal direction.
Moreover, Patent Document No. 4 describes a compact electric vehicle in which the power battery is accommodated in the space formed in a generally quadrilateral portion of the body frame located in the body center so as to achieve battery protection, space efficiency, and mass localization.